Envelope tear-strip applying-machine



[761127, 1968 G. A. STILPHEN ETAL 3,371,007

ENVELOPE TEAR-STRIP APPLYINGMACHINE Filed Dec. 23, 1964 NN. s mPP fin VTTIM mSS AH G RR 00 v G6 8 lllll lk iwl ng WW United States Patent 3,371,007 ENVELOPE TEAR-STRIP APPLYING-MACHINE George A. Stilphen and George H. Stilphen, both of 36 Nevins St, Portland, Maine @4103 Filed Dec. 23, 1964, Ser. No. 420,678 1 Claim. (Cl. 156-498) This invention relates to a machine for the application of tear-strips to envelopes to facilitate the subsequent opening thereof after the sealing shut of the fiap.

The main main objects of this invention are to provide an improved machine for the automatic application of tear-strips along the creases of the sealing flaps of envelopes; to provide an improved machine of this kind for the sealed application of a thin, narrow strip of thermoplastic material; and to provide an improved tear-strip applying machine of this kind of such simple construction as to make very economical its marketing and extremely facile its operation for applying the tearstrips to various sizes of envelopes.

In the adaptation shown in the accompanying drawings;

FIGURE 1 is a plan view of an improved envelope tear-strip applying machine constructed in accordance with this invention;

FIGURE 2 is a side elevation of the same;

FIGURE 3 is a vertical, sectional elevati-onal view taken on the plane of the line 3--3 of FIGURE 1;

FIGURE 4 is a side elevational view illustrating the perforating disk and one of the plurality of rollers; and

FIGURE 5 is a top plan view of FIGURE 4.

The essential concept of this invention involves the heated application of a tear-strip of thermoplastic material along the flap crease of a conveyed-succession of open-flap envelopes for the subsequent use in tearing open or slitting of the sealed envelopes.

The envelope tear-strip applying-machine embodying the foregoing concept comprises a frame A, a conveyor mechanism B, a strip applicator C, a strip-cutting device D and an envelope stacking magazine E.

The frame A, as herein shown, comprises a longitudinally-disposed base part 5 supported, at its ends, by suitablybraced legs 6 at approximately normal waist height above the floor.

The conveyor B comprises an envelope-receiving section 7 and the envelope-advancing section 8 arranged in horizontal alignment and interconnected by synchronized sprocket and chain driving means, the nature of which will be described presently.

The envelope-receiving section 7, as here shown, is arranged at the left of the frame A and could involve almost any conventional form of conveyor flights. These might be in the form of a belt traversing spaced pulleys or chains traversing spaced and aligned sprockets, the latter is diagrammatically indicated at the left of FIG- URES 1 and 2. Whatever its nature such a section 7 would have appropriately-spaced, upwardly-extending guides between which the envelopes would be successively deposited by any conventional form of envelopefeeding device. Such an envelope-feeding device would deposit the envelopes on the conveyor 9 with the flaps open, as indicated in dotted outline in FIGURE 1.

The envelope-advancing conveyor section 8; as here shown, comprises a narrow, endless belt 10 with a longitudinally-spaced and aligned series of spring-biased rollers 11 pressured against the inner face of the lower flight of the belt 10. The lower flight of belt 10 is positioned slightly above the table 5a on which the envelopes are moved longitudinally to the right of FIGURE 1. These rollers are each journaled on a support 111 secured at the lower end to the frame A and serve to slightly 3,371,007 Patented Feb. 27, 1968 pressure that lower flight of the upper belt against the table top. Such a series of spring-biased rollers 11 ensures proper spacing of the envelopes and simultaneously move them along the table top during the application of the strip material 12 to the passing envelopes, and later permitting the proper severance of the strip material 12 between the spaced envelopes. Each roller is splined to shaft 112 and driven by sprocket 113 and an appropriate chain and sprocket (not shown) as will be hereinafter explained.

The strip material 12 is a thin, narrow thermoplastic or thermoseal material which with the application of a proper degree of heat becomes softened enough to become sticky and adhere to the flap of the envelope. The heating, however, does not alter the form of the strip material; it merely secures a condition that results in the adherence to the envelope suflicient to ensure the subsequent use in ripping open the envelope along the sealed flap crease. A preferred material is the commercially known Mylar of approximately to a of an inch Wide.

The synchronized operation of the two conveyor sections 7 and 8 is effected through a suitable interconnection of chain belts operating over a series of sprockets as illustrated herein. Such interconnections involve a chain belt 13 traveling over sprockets 14 and 15, keyed to the respective shafts 16 and 17 journaled adjacent the opposed ends of the conveyor sections 7 and 8; an endless chain belt 18 operating over sprockets 19 and 20 respectively keyed to shafts 17 and 21 journaled at the opposite ends of the frame base 5; and the vertically-disposed chains 22 and 23 operating over the respective series of sprockets 24, 25 and 26 and 27, 28 and 29 at the opposite ends of the frame base 5 (FIGURE 1). The sprocket 27 is driven by an endless chain 30 operating over sprocket 19 on shaft 17 a sprocket 31 on the shaft 21 (FIGURE 1), sprocket 113 on shaft 112 and sprocket 67 on shaft 68 (FIG- URE 4).

The strip applicator C includes a reel 32, a heated wheel 33 and intermediate strip-guide means 34.

The reel 32 is journaled on a shaft fixed at the upper end of a bracket 36 secured to the front side of the frame A. The wheel 33 is journaled on a shaft fixed at the upper end of a second bracket 37 attached to the front side of the frame A, rearwardly of the bracket 36.. The wheel 33 is in the form of a narrow disk and mounts on one face thereof a heating element 38. The heating element 38 is controlled by a suitable means (not shown) connected to a thermostatically-controlled source of electrical current. The wheel 33 is driven from a sprocket 39, on the shaft 40 mounting the sprocket 26, and a chain 41 leading to a sprocket 42 on the shaft of the wheel 33.

The strip-guide means 34'herein is shown as a rockerarm the hub 44 of which is journaled on the shaft for the wheel 33 and mounting a pair of grooved rollers 46 and 461 over which the strip material 12 is guided to the applicator wheel 33.

The strip-cutting device D includes a knife blade 47 (FIGURE 1) fixed to a hub 44 secured to the end of a shaft 48 journaled in a pair of spaced bearings 49. The knife blade 47 extends through a slot in the table 5a of the frame A. It is positioned to sever the strip material 12 extending between adjacent envelopes after being applied to the envelopes by the heat wheel 33. The knife blade 47 is rotated by a chain sprocket and gear mechan sm 50 (shown at the left of FIGURE 1) driven from the shaft 16. It should be understood that the knife is rotated in timed relation with the movement of the envelopes so as to sever the strip 12 extending between the envelopes to form tabs on each end of every envelope.

The base part 5 of the frame A mounts an adjustable guide rail 51 and a flap-closing deflector 52 as best seen in FIGURE 1. The guide rail 51 extends along the front of the base part 5 and has a pair of longitudinally-spewed slots 53 seating screws 54 which permit fixing the position of the guide rail 51 to dispose envelopes of differing sizes in proper position to have the strip material 12 applied directly along the flap crease.

The flap deflector 52, as best shown at the right of FIGURE 1, is a strip of rigid material twisted and so positioned as to engage the open flap of the advancing envelope and turn the flap inwardly and down against the body of the envelope as it approaches its discharge into the stacking magazine E. In order to cool the strip 12 prior to folding the envelope flap back on the envelope, means are provided to blow air on the strip 12 during movement and subsequent to cutting. This means is a pump, not shown, from which tube 64 extends to direct the air on the strip 12, as shown in FIGURES 1 and 2.

The stacking magazine E involves a chute 56 and a slotted transfer rotor 57. The chute 56 is attached to the frame A to extend outwardly in alignment with the conveyor section 8, but with the bottom of the chute disposed an appreciable distance below the belts 9 and 1%. The slotted rotor, as herein shown, comprises a conventional arrangement of a pair of axially-spaced plates 561 in which shaft 58 is journalled. The shaft 58 is driven by a chain 59 operating over sprockets 60 and 61, respectively, connected to the shaft 21, of the conveyor section 8, and the shaft 58, respectively. These rotor plates have a series of narrow slots 62 extending inwardly from the peripheries. The slots 62 are so arranged and the shaft 58 is so positioned that the slots 62 are successively aligned with the envelope-discharge end of the table 5a (see FIG- URE 2) and subsequently the envelopes F disposed vertically of the bottom of the chute 56. The operation of the envelope tear-strip applicator is as follows:

Envelopes F, with their flaps laid open, are discharged onto the conveyor section 7 from which they are successively advanced to and move through the conveyor section 8. During such advance of each envelope the applicator wheel 33 presses the strip material 12 against the envelope adjacently along the flap crease. The heating of the strip material, by the wheel 33, is just enough to soften the material so that it becomes sticky at the point of pressured contact between the periphery of the wheel and the envelope. Immediately upon passing the applicator wheel 33 the strip material quickly cools and becomes fixed along the flap crease. As the stripped envelopes pass beyond the applicator wheel 33 the knife blade 47 severs the strip material 12. As the envelopes further move on the table they approach the flap deflector 52 and each flap is turned inwardly down into normal position against the body of the envelope. Thereupon, the envelopes are discharged into the slots 62 in the rotor 57 from whence they are deposited in the chute 56, in a Well-known manner.

In the event it is desirable, the flap may be provided with a series of spaced perforations immediately adjacent the area where the strip 12 will be attached. This is accomplished by providing a wheel 63 provided with a series of space cutters. The wheel is mounted on shaft 66. Associated with appropriate sprocket mechanism to sprocket 67 positioned between the flights of chain 18. Thus, as the envelope, with its flap opened, moves from conveyor '7 to the table and below the lower flight of the belt 1%, and because of the rollers 11 acting on the inner surface of the lower flight, t .e envelope is caused to move toward the right (as viewed in FIGURE 1) to be engaged by the perforator wheel 63, and thence to the applicator wheel as above described.

It should now be apparent that a pair of spaced perforator wheels may be used if it is desirable to perforate the flap on both sides of the strip 12.

Although but one specific embodiment of this invention is herein shown and described it will be understood that details of the construction shown may be altered or omitted without departing from the spirit of the invention as defined by the following claim.

We claim:

1. A machine, for the automatic application of heated strips of thermoseal material adjacently along the flap creases of a conveyed succession of ope -fiap envelopes, comprising,

(a) supporting frame,

(b) a conveyor mounted on the frame to receive at one end a controlled succession of envelopes with their sealing flaps retracted,

(c) a magazine adjacent the opposite end of the conveyor for stacking the stripped envelopes,

(d) a heated strip-applicator juxtaposed to the conveyor to soften the strip and to adhere the strips along the flap-creases of the envelopes,

a said applicator comprising a disc wheel positioned to apply the strip material adjacently along the flap crease and mounts a thermostatic-controlled heating element,

(e) means for the controlled feeding of the thermoseal strip material to the heated applicator,

(f) a series of spaced rollers associated with said conveyor to space the envelopes during movement along the conveyor,

(g) a perforator disk to apply a series of spaced perforations along the envelope flap immediately adjacent the area where the strips are applied,

(h) air cooling means for cooling said strip after application to the envelop flap, and

(i) means for severing said strip between the envelopes subsequent to the application by the applicator.

References Cited UNITED STATES PATENTS DOUGLAS 3'. DRUMMOND, Primary Examiner. 

1. A MACHINE, FOR THE AUTOMATIC APPLICATION OF HEATED STRIPS OF THERMOSEAL MATERIAL ADJACENTLY ALONG THE FALP CREASES OF A CONVEYED SUCCESSION OF OPEN-FLAP ENVELOPES, COMPRISING, (A) SUPPORTING FRAME, (B) A CONVEYOR MOUNTED ON THE FRAME TO RECEIVE AT ONE END A CONTROLLED SUCCESSION OF ENVELOPES WITH THEIR SEALING FLAPS RETRACTED, (C) A MAGAZINE ADJACENT THE OPPOSITE END OF THE CONVEYOR FOR STACKING THE STRIPPED ENVELOPES, (D) A HEATED STRIP-APPLICATOR JUXTAPOSED TO THE CONVEYOR TO SOFTEN THE STRIP AND TO ADHERE THE STRIPS ALONG THE FLAP-CREASES OF THE ENVELOPES, A SAID APPLICATOR COMPRISING A DISC WHEEL POSITIONED TO APPLY THE STRIP MATERIAL ADJACENTLY ALONG THE FLAP CREASE AND MOUNTS A THERMOSTATIC-CONTROLLED HEATING ELEMENT, (E) MEANS FOR THE CONTROLLED FEEDING OF THE THERMOSEAL STRIP MATERIAL TO THE HEATED APPLICATOR, (F) A SERIES OF SPACED ROLLERS ASSOCIATED WITH SAID CONVEYOR TO SPACE THE ENVELOPES DURING MOVEMENT ALONG THE CONVEYOR. (G) A PERFORATOR DISK TO APPLY A SERIES OF SPACED PERFORATIONS ALONG THE ENVELOPE FLAP IMMEDIATELY ADJACENT THE AREA WHERE THE STRIPS ARE APPLIED, (H) AIR COOLING MEANS FOR COOLING SAID STRIP AFTER APPLICATION TO THE ENVELOP FLAP, AND (I) MEANS FOR SEVERING SAID STRIP BETWEEN THE ENVELOPES SUBSEQUENT TO THE APPLICATION BY THE APPLICATOR. 